IP Library › Granted Patent US 12,573,987
Granted Patent B2
US 12,573,987 · App. 18/111,767 · Granted Mar 10, 2026

Apparatuses and methods involving frequency-selective power amplification

Inventors: Juan Rivas-Davila (Palo Alto, CA); Jiale Xu (Stanford, CA); Kawin Surakitbovorn (Menlo Park, CA); Benjamin Wang (Stanford, CA); Mark A. Cappelli (Stanford, CA)
Assignee: The Board of Trustees of the Leland Stanford Junior University
H03F3/2176H05H1/2406H03F1/56H03F2200/387H03F2200/451H05H2242/24H05H2242/26
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Quick Facts
Patent No.
US 12,573,987
App. No.
18/111,767
Granted
Mar 10, 2026
Kind
B2
Abstract

In certain examples, methods and semiconductor structures are directed to a switching (power) amplification circuit, including resonance circuitry to resonate at a frequency associated with at least one of a plurality of different selectable resonance frequencies. The switching amplification circuit is configured to deliver power to one or multiple loads while the switching amplifier circuit is operating based on one or more of the selectable resonance frequencies.

Claims (26)

1 . An apparatus comprising:

a switching amplifier circuit, that is frequency selective and includes resonance circuitry to resonate at a frequency associated with a plurality of different selectable resonance frequencies, to deliver power to at least one load, including a frequency-reactive load, while the switching amplifier circuit is operating based on a plurality of different switching frequencies;

a first resonant network, as part of the resonance circuitry, to resonate at a first frequency associated with one of the plurality of different selectable resonance frequencies and with the at least one load; and

a second resonant network, as part of the resonance circuitry, to resonate at a second frequency associated with another one of the plurality of different selectable resonance frequencies and with said at least one load,

wherein the switching amplifier circuit is to drive the at least one load using at least two distinct frequencies, from among the plurality of different switching frequencies, in a frequency-controllable or frequency-alternating manner, to cause generation of plasma at said at least one load in response to the first resonant network resonating at the first frequency and the second resonant network resonating at the second frequency.

2 . The apparatus of claim 1 , wherein the switching amplifier circuit is a Class E power amplifier, and each of the plurality of different switching frequencies is on the order of a MegaHertz.

3 . A method comprising:

driving at least one load including a frequency-reactive load, via a switching amplifier circuit that is frequency selective and ZVS (zero voltage switching) and includes resonance circuitry to resonate at a frequency associated with a plurality of different selectable resonance frequencies, and delivering power to the at least one load while the switching amplifier circuit is operating based on at least one of a plurality of different switching frequencies, wherein the resonance circuitry includes a first resonant network operable to resonate at a first frequency associated with one of the plurality of different selectable resonance frequencies and a second resonant network operable to resonate at a second frequency associated with another one of the plurality of different selectable resonance frequencies; and

driving, via the switching amplifier circuit, the at least one load using at least two distinct frequencies, from among the plurality of different switching frequencies, in a frequency-controllable or frequency-alternating manner, to cause generation of plasma at said at least one load in response to the first resonant network resonating at the first frequency and the second resonant network resonating at the second frequency.

4 . The apparatus of claim 1 , further including at least one dielectric barrier discharge (DBD) load corresponding to said at least one load; and a frequency-generating signal circuit to provide at least one signal to the switching amplifier circuit at one or more of the plurality of different switching frequencies.

5 . The apparatus of claim 1 , wherein the at least one load includes a wireless-signal generator.

6 . The method of claim 3 , further including using the switching amplifier circuit and the at least one load in a cooperative manner to generate plasma-based fertilizer.

7 . The apparatus of claim 1 , wherein the different switching frequencies are in a frequency range that includes one or more frequencies which are greater than or equal to 100 kHz.

8 . The apparatus of claim 1 , wherein the different switching frequencies are in a frequency range that includes one or more frequencies which do not exceed a frequency beyond an order of megahertz (MHz).

9 . The apparatus of claim 1 , wherein the different switching frequencies are in a frequency range that includes one or more frequencies which are greater than or equal to 1 megahertz (MHz) and which do not exceed a frequency of 20 MHz.

10 . The apparatus of claim 1 , wherein the resonance circuitry is settable to resonate at a selected one of the plurality of different selectable resonance frequencies for delivering power to said at least one load which has a design feature linked to the selected one of the plurality of different selectable resonance frequencies.

11 . The apparatus of claim 1 , wherein the at least one load includes a first load and a second load, and the resonance circuitry includes reactance-compensation circuitry to mitigate delivery of power, from the switching amplifier circuit, to the first load being different than to the second load.

12 . The apparatus of claim 1 , wherein the at least one load includes a first load and a second load, and the switching amplifier circuit is to mitigate delivery of respective amounts of power, from the switching amplifier circuit, to the first load being different than to the second load.

13 . The apparatus of claim 1 , wherein the at least one load includes a first load and a second load, and the switching amplifier circuit is to deliver power to the first load by presenting a first voltage level to the first load and by presenting a second voltage level to the second load, wherein the first voltage level is sufficiently greater than the second voltage level so that only one of the first load and the second load is in active use at any given time.

14 . An apparatus comprising:

a switching amplifier circuit, including resonance circuitry to resonate at a frequency associated with a plurality of different selectable resonance frequencies, to deliver power to at least one load while the switching amplifier circuit is operating based on at least one of a plurality of different switching frequencies; and wherein the switching amplifier circuit is characterized by an output impedance Z out that is constant at a first one and at a second one of the plurality of different selectable resonance frequencies, and wherein the resonance circuitry includes components to realize the output impedance Z out .

15 . The apparatus of claim 1 , wherein the at least one load includes a first load and a second load and the switching amplifier circuit is to operate according to at least two of the following attributes: the switching amplifier circuit being configured to mitigate delivery of respective amounts of power, from the switching amplifier circuit, to the first load being different than to the second load; the switching amplifier circuit being configured to mitigate causing the first load and the second load to be in active use at any given time by presenting respective voltage levels to the first load and the second load; and the resonance circuitry being configured with components to realize a switching-amplifier-circuit output impedance Z out that is constant at a first one and at a second one of the plurality of different selectable resonance frequencies.

16 . The apparatus of claim 1 , further including an output resistance coupled to the switching amplifier circuit, wherein the switching amplifier circuit is characterized by an output impedance Z out that is constant at a first one and at a second one of the plurality of different selectable resonance frequencies, and the output resistance is matched to the output impedance Z out .

17 . The method of claim 3 , further including using the switching amplifier circuit and the at least one load in a cooperative manner to generate a plasma via a plasma-assisted nitrogen reaction, while the switching amplifier circuit realizes a peak efficiency of greater than 85% and output 600 Watts at one or more frequencies in a range 9 MHz to 20 MHz.

18 . The method of claim 3 , wherein the at least one load includes different loads, and the method further includes compensating, via reactance-compensation circuitry, for differences in amounts of power being delivered, from the switching amplifier circuit, to the different loads.

19 . The method of claim 3 , further including using the switching amplifier circuit and the at least one load in a cooperative manner to generate plasma via a plasma-assisted nitrogen reaction occurring at less than 400° C. and under pressure of less than 15 megapascals.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 4, 2025
From: RIVAS-DAVILA, JUAN; XU, JIALE; SURAKITBOVORN, KAWIN; WANG, BENJAMIN; CAPPELLI, MARK A.
To: THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIVERSITY
Reel/Frame 070107/0459 →
Continuity (2)
Provisional Application 63316878 · Mar 4, 2022
Related Publication 20230283249A1 · Sep 7, 2023
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